The immune checkpoint inhibitors treatment of head and neck squamous cell carcinoma: an expert consensus.

Immune checkpoint inhibitors (ICIs) present significant efficacy in the treatment of malignant tumors, and they have been approved as the first-line of treatment for various cancers. Pembrolizumab monotherapy or combined with chemotherapy has been recommended by domestic and foreign guidelines for the first-line treatment of recurrent/metastatic head and neck squamous cell carcinoma. Although ICIs represent a milestone in the treatment of head and neck squamous cell carcinoma, potential problems still need to be addressed, such as the selection of the efficacy predictors for ICIs, the evaluation of the tumor response to ICIs, and the treatment of immune hyperprogression and immune-related adverse events. Therefore, to form a relatively unified understanding of ICIs treatment for head and neck squamous cell carcinoma, we integrated the clinical experience of multi-disciplinary experts of head and neck cancers on the basis of current clinical hot issues and finally developed this consensus.

EGF/EGFR Promotes Salivary Adenoid Cystic Carcinoma Cell Malignant Neural Invasion via Activation of PI3K/AKT and MEK/ERK Signaling.

BACKGROUND: Salivary adenoid cystic carcinoma (SACC) is one of the most common malignant cancers of the salivary gland, and 32.4-72.0% of SACC cases exhibit neural invasion (NI); however, the molecular mechanism underlying the high invasion potential of SACC remains unclear. METHODS: The present study investigated the role of epidermal growth factor receptor (EGFR) in the AKT inhibition- or mitogen-activated protein kinase kinase (MEK)-induced NI and epithelialmesenchymal transition (EMT) in SACC cells using EGFR, PI3K, and MEK inhibitors. SACC-83 cell viability was assessed using an MTT assay, and a wound healing assay was performed to evaluate cell migration. Immunohistochemical staining with streptavidin peroxidase was used to detect the positive expression rate of EMT, AKT, phosphorylated (p)-AKT, ERK, and p-ERK proteins. The impact of EGFR, PI3K, and MEK inhibitors on tumor growth and NI was examined in a xenograft model in nude mice. RESULTS: EGF and EGFR are effective in increasing cell viability, migration, and invasion. SACC metastasis is affected by the PI3K/AKT and MEK/ERK pathways, both of which are initiated by EGF/EGFR. The EMT and NI are regulated by the EGF/EGFR, PI3K/AKT, and MEK/ERK pathways. The present findings demonstrate the importance of suppressed EGFR/AKT/MEK signaling in NI in SACC by neural-tumor co-culture in vitro. Furthermore, our preclinical experiment provides solid evidence that injection of EGFR, PI3K, and MEK inhibitors suppressed the tumor growth and NI of SACC cells in nude mice. CONCLUSION: It was identified that inhibitors of EGFR, PI3K/AKT or MEK/ERK suppressed the proliferation, migration, and NI of SACC-83 cells via downregulation of the PI3K/AKT or MEK/ERK pathways. It was also demonstrated that inhibition of EGFR abolishes EMT in SACC by inhibiting the signaling of PI3K/AKT and MEK/ERK. The present results suggest the potential effectiveness of targeting multiple oncogenes associated with downstream pathways of EGF/EGFR, as well as potential therapeutic targets to limit NI in SACC by PI3K/AKT or MEK/ERK inhibition.

[Multidisciplinary team model for patients with oral cancer and systemic diseases: an expert consensus].

Large general hospitals currently play an increasingly important role in the diagnosis and treatment for acute critical patients and difficult diseases because of the development of dual referral system and hierarchical diagnosis, as well as the formation of medical treatment alliance. Patients with oral cancers are often associated with systemic diseases, which increases the complexity of the condition. Thus, meeting the demand through the traditional single medical model is difficult. As such, a multidisciplinary team (MDT) model has been proposed and has achieved a good clinical effect. To standardize the application of this model, we organized an event in which relevant experts discussed and formulated a consensus to provide standardized suggestions on the MDT process and the diagnosis and treatment of common systemic diseases as reference for clinical practice.

Embolization and sclerotherapy of maxillofacial arteriovenous malformations with the use of fibrin glue combined with pingyangmycin.

OBJECTIVE: The objectives of this study were to document the results of using fibrin glue (FG) combined with pingyangmycin (PYM) for the embolism and sclerotherapy of maxillofacial arteriovenous malformations (AVMs). STUDY DESIGN: We reviewed the associated clinical data from December 2012 to June 2017 for 25 patients with maxillofacial AVMs. The major treatment method was direct percutaneous puncture and injection of FG combined with PYM. Treatment outcomes were assessed through physical examination, Doppler ultrasonography, computed tomography, and 3-dimensional computed tomography angiography scans. Follow-up time ranged from 12 months to 3 years after the last treatment (mean 21 months). RESULTS: Of the 25 lesions, 80% showed greater than 90% reduction, 12% showed greater than 75% reduction, and 8% showed greater than 50% reduction. Superficial skin necrosis or mucous ulcer occurred in 3 patients and healed without intervention. Regrowth was observed in 3 patients with extensive lesions involving multiple anatomic regions. CONCLUSIONS: These data suggest that embolization and sclerotherapy with the use of FG combined with PYM are safe and effective for the treatment of small- to medium-sized, locally dilated maxillofacial AVMs. For AVMs involving multiple anatomic regions, combined application of this approach with other options should be considered.

Sympathetic innervation contributes to perineural invasion of salivary adenoid cystic carcinoma via the ß2-adrenergic receptor.

PURPOSE: Perineural invasion (PNI) is reported to correlate with local recurrence and poor prognosis of salivary adenoid cystic carcinoma (SACC). However, the pathogenesis of PNI remains unclear. The aims of this study were to investigate the correlation between sympathetic innervation and SACC PNI and to elucidate how the sympathetic neurotransmitter norepinephrine (NE) regulates the PNI process. MATERIALS AND METHODS: Sympathetic innervation and ß2-adrenergic receptor (ß2-AR) expression in SACC tissues were evaluated by immunohistochemistry. The NE concentrations in SACC tissues and dorsal root ganglia (DRG) coculture models were measured by ELISA. ß2-AR expression in SACC cells was detected by performing quantitative real-time polymerase chain reaction (qRT-PCR) and immunofluorescence assay. SACC cells were treated with NE, the nonselective α-AR blocker phentolamine, the ß2-AR antagonist ICI118,551, or were transfected with ß2-AR small interfering RNA (siRNA). Proliferation was evaluated in methyl thiazolyl tetrazolium assay, and migration was evaluated in Transwell assay and wound-healing assay. PNI was tested through both Transwell assay and a DRG coculture model. The expressions of epithelial-mesenchymal transition (EMT) markers and matrix metalloproteinases (MMPs) were measured by performing qRT-PCR and Western blot assay. RESULTS: Sympathetic innervation and ß2-AR were highly distributed in SACC tissues and correlated positively with PNI (P=0.035 and P=0.003, respectively). The sympathetic neurotransmitter NE was overexpressed in SACC tissues and DRG coculture models. Exogenously added NE promoted proliferation, migration, and PNI of SACC cells via ß2-AR activation. NE/ß2-AR signaling may promote proliferation, migration, and PNI by inducing EMT and upregulating MMPs. However, ß2-AR inhibition with either an antagonist or siRNA abrogated NE-induced PNI. CONCLUSION: Collectively, our findings reveal the supportive role of sympathetic innervation in the pathogenesis of SACC PNI and suggest ß2-AR as a potential therapeutic target for treating PNI in SACC.

CRNDE promotes cell tongue squamous cell carcinoma cell growth and invasion through suppressing miR-384.

Tongue squamous cell carcinoma (TSCC) is the most common type of oral cancer and is an aggressive head and neck malignancy. Increasing studies have demonstrated that long noncoding RNAs (lncRNAs) play important roles in diverse biological cell processes, such as cell development, fate decisions, cell differentiation, cell migration, and invasion. In our study, we showed that long noncoding RNA colorectal neoplasia differentially expressed (CRNDE) expression was upregulated in TSCC cell lines and tissues. Overexpression of CRNDE increased the TSCC cell proliferation, cell cycle, and cell invasion. Moreover, ectopic expression of CRNDE inhibited the miR-384 expression in the SCC1 cell and increased the Kirsten Ras (KRAS), cell division cycle 42, and insulin receptor substrate 1 expression, which were the direct target genes of miR-384. We demonstrated that the miR-384 expression was downregulated in the TSCC samples compared with the paired adjacent nontumor samples. The expression of CRNDE was negatively correlated with the expression of miR-384 in the TSCC samples. Overexpression of miR-384 suppressed TSCC cell proliferation, cell cycle, and invasion. Furthermore, we demonstrated that CRNDE promoted TSCC cell proliferation and invasion through inhibiting miR-384 expression. These results suggested that CRNDE acts as an oncogene in the development of TSCC, which partially occurs through inhibiting miR-384 expression.

The CCL5/CCR5 Chemotactic Pathway Promotes Perineural Invasion in Salivary Adenoid Cystic Carcinoma.

PURPOSE: Perineural invasion (PNI) is a hallmark of salivary adenoid cystic carcinoma (SACC) and represents an important risk factor for local recurrence and poor survival. However, the mechanism of PNI has yet to be explored. We sought to examine the CCL5-CCR5 ligand-receptor interaction between nerves and SACC cells. MATERIALS AND METHODS: CCL5/CCR5 expression was determined by immunohistochemistry in SACC tissue specimens. The correlations between CCL5/CCR5 expression and clinicopathologic features were investigated. Dorsal root ganglia (DRG) and SACC cells cocultured in vitro were used to evaluate the effects of CCL5/CCR5 on PNI progression and pathogenesis. RESULTS: CCR5 expression was significantly elevated in SACC tissues and associated with distant metastasis, PNI, and TNM grade (P < .05). DRG and SACC cells cocultured in vitro showed that the activation of the CCL5/CCR5 axis significantly increased SACC cell invasion and promoted the outgrowth of the DRG. SACC cell lines expressing CCR5 migrated in response to CCL5 derived from DRG, eventually leading to PNI. More importantly, further study showed that blocking of CCL5 or CCR5 effectively inhibited the invasive capacity and PNI activity of SACC cells (P < .05). CONCLUSIONS: Our results suggest a pivotal role of CCL5/CCR5 axis in tumor-nerve interactions during PNI of SACC. The CCL5/CCR5 pathway might prove to be an attractive new target for the treatment of SACC with PNI.

The "Flap Suture Anchoring" Technique for Safe Oral Floor Reconstruction With Preservation of Alveolar Process.

Flaps-based microsurgery is routinely applied to reconstruct oral floor defects caused by oncologic resection. To prevent orocutaneous fistulae, flaps are frequently sutured with buccal vestibule mucosa after sacrificing the alveolar process. The patients suffered denture loss and irreversible structural damage. For reliable oral floor reconstruction with preservation of alveolar process, the authors introduced the flap "suture anchoring" technique. Oral floor, hemiglossal-oral floor, and tongue base-parapharyngeal wall-oral floor defects were included in this study. The flap anchoring technique involves structural oral floor reconstruction with a chimeric anterolateral thigh-free flap or radial forearm flap with adipofascial tissue extension. The dead space in oral floor is filled with vastus lateralis muscle or adipofascial tissue, then holes are drilled on the alveolar bone among tooth root, beneath the attached gingiva. Skin paddle is sutured with 4-0 sutures through the alveolar holes thus anchored to the mandible. By applying this technique, there was no wound infection or orocutaneous fistulae in all patients postoperatively, even experienced postoperative radiotherapy. In addition, a soft and natural jaw-tongue furrow could be formed to allow the free movement of tongue. Taken together, the flap anchoring technique offers a safe and reliable approach to recover oral function and preservation of occlusion.

High Expression of Prospero-Related Homeobox-1 (PROX1) Is Associated With Poor Prognosis in Patients With Salivary Adenoid Cystic Carcinoma.

PURPOSE: Prospero-related homeobox-1 (PROX1) plays an important role in the invasion and metastasis of many human cancers. However, the expression pattern of PROX1 in salivary adenoid cystic carcinoma (SACC) remains unclear. The aim of this study was to investigate PROX1 expression and its prognostic value in SACC. MATERIALS AND METHODS: PROX1 expression was determined by immunohistochemistry (IHC) in SACC tissue specimens. Correlations between PROX1 expression and clinicopathologic features were investigated. The Kaplan-Meier method was used to analyze the correlation between PROX1 expression and survival. Independent prognostic factors associated with overall survival (OS) were analyzed using Cox regression analysis. RESULTS: The IHC data showed that the PROX1 positivity rate in SACC tissue specimens was significantly higher than that in normal salivary gland tissues (71.1 vs 13.3%; P < .05). PROX1 expression was detected mainly in the nucleolus. In addition, PROX1 expression was correlated with perineural invasion, local regional recurrence, and distant metastasis of patients with SACC (P < .05), and no significant association was found between PROX1 expression and other clinicopathologic parameters. Data indicated that patients with positive PROX1 expression had poor OS compared with those with negative PROX1 expression (P = .0005). Multivariate analysis showed that PROX1 expression, local regional recurrence, and distant metastasis were independent prognostic factors for OS. CONCLUSIONS: These findings showed that PROX1 expression was statistically higher in SACC specimens. Positive expression of PROX1 might serve as a potential predictor of prognosis in SACC.

The Neuropilins and Their Ligands in Hematogenous Metastasis of Salivary Adenoid Cystic Carcinoma-An Immunohistochemical Study.

PURPOSE: We investigated the expression of neuropilin-1 (NRP1), neuropilin-2 (NRP2), vascular endothelial growth factor-A (VEGF-A), semaphorin-3A (Sema-3A), and semaphorin-3F (Sema-3F) in normal salivary gland (NSG) tissue, nonmetastatic salivary adenoid cystic carcinoma (SACC), and metastatic SACC to better understand their role in intratumoral angiogenesis and hematogenous metastasis of SACC. PATIENTS AND METHODS: The study included 60 SACC patients, equally divided between nonmetastatic SACC and metastatic SACC. We used 30 NSG samples as the control. The expression of cytokines was studied by immunohistochemistry and compared using the integrated optical density. The relationship between NRP1, NRP2, VEGF-A, and Sema-3A expression and microvessel density (MVD) was analyzed in the 3 groups. RESULTS: In metastatic SACC, the expression levels of NRP1 and VEGF-A were significantly greater than those in nonmetastatic SACC and NSG. The expression of Sema-3A and Sema-3F was significantly lower in metastatic SACC than that in nonmetastatic SACC and NSG (P < .0001). No significant differences were found in NRP2 expression among the 3 groups (P = .43). The MVD of metastatic SACC was significantly greater than that of nonmetastatic SACC and NSG (P < .0001). However, the lymphatic vessel density of the 3 groups was not significantly different statistically. The relationship between MVD and NRP1 or VEGF-A showed a significant positive correlation (P < .0001, for both). However, a significant negative correlation was found between the MVD and Sema-3A or Sema-3F expression (P < .0001, for both). CONCLUSIONS: Hematogenous metastasis of SACC is correlated with high expression of NRP1 and VEGF-A and low expression of Sema-3A and Sema-3F. The increased numbers of microvessels induced by VEGF-A signaling, combined with NRP1, could be one of the key reasons leading to the enhanced hematogenous metastasis in SACC.

Preventing Early-Stage Graft Bone Resorption by Simultaneous Innervation: Innervated Iliac Bone Flap for Mandibular Reconstruction.

BACKGROUND: Postoperative resorption of vascularized bone grafts jeopardizes the success of dental implant(s) and functional rehabilitation of the jaw. Recent evidence supports the crucial role of innervation in bone regeneration and turnover. METHODS: This study reports a new technique for simultaneous innervation of vascularized iliac flaps in mandibular reconstruction, through neurorrhaphy between ilioinguinal nerves, which innervate iliac bone, and inferior alveolar nerves or great auricular nerves. Twenty-two patients (aged 50 to 69 years) with postoncologic continuity defects of the mandible underwent mandibular reconstruction (10 innervated flaps and 12 control flaps). Graft bone resorption was analyzed by computed tomographic scans at 6 and 12 months postoperatively, and bone quality was evaluated for dental implantation, with histologic and histomorphometric analyses for graft samples. RESULTS: At 12-month follow-up, graft bone density loss in the control group was significantly higher than in the innervated group (p < 0.05). Bone quality evaluation indicated a suitable condition for dental implantation in all patients in the innervated group but in 41.7 percent of patients in the control group. Histologic and histomorphometric analyses showed successful innervation in the innervated group but not in the control group. Osteoclast activity was significantly higher in the control group than in the innervated group (p < 0.05). CONCLUSIONS: Innervated iliac flaps may effectively prevent bone resorption of grafts in mandible reconstruction that otherwise jeopardize the success of dental implants. This new strategy of innervation of bone flaps appears clinically valuable and provides insights into the homeostasis of grafts for functional reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Nomograms to estimate long-term overall survival and tongue cancer-specific survival of patients with tongue squamous cell carcinoma.

The aim of this study was to construct nomograms to predict long-term overall survival (OS) and tongue cancer-specific survival (TCSS) of tongue squamous cell carcinoma (TSCC) patients based on clinical and tumor characteristics. Clinical, tumor, and treatment characteristics of 12,674 patients diagnosed with TSCC between 2004 and 2013 were collected from the Surveillance, Epidemiology, and End Results database. These patients were then divided into surgery and nonsurgery cohorts, and nomograms were developed for each of these groups. The step-down method and cumulative incidence function were used for model selection to determine the significant prognostic factors associated with OS and TCSS. These prognostic variables were incorporated into nomograms. An external cohort was used to validate the surgery nomograms. Seven variables were used to create the surgery nomograms for OS and TCSS, which had c-indexes of 0.709 and 0.728, respectively; for the external validation cohort, the c-indexes were 0.691 and 0.711, respectively. Nine variables were used to create the nonsurgery nomograms for OS and TCSS, which had c-indexes of 0.750 and 0.754, respectively. The calibration curves of the 5- and 8-year surgery and nonsurgery nomograms showed excellent agreement between the probabilities and observed values. By incorporating clinicopathological and host characteristics in patients, we are the first to establish nomograms that accurately predict prognosis for individual patients with TSCC. These nomograms ought to provide more personalized and reliable prognostic information, and improve clinical decision-making for TSCC patients.

Overexpression of KAI1/CD82 suppresses in vitro cell growth, migration, invasion and xenograft growth in oral cancer.

KAI1/CD82 is a metastatic suppressor gene in human prostate cancer and several other types of cancer in humans. The present study aimed to examine the role of the overexpression of KAI1 in the progression of oral cancer. Human KAI1/CD82 cDNA was transfected into OSCC­15 and 293T cell lines, and its effects on OSCC­15 cell proliferation, invasion and apoptosis were assessed by performing a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, Matrigel invasion and Annexin V­FITC staining, respectively. In addition, a xenograft model was used to assess the effect of KAI1/CD82 on the in vivo growth of tumors. The overexpression of KAI1/CD82 inhibited the proliferation and invasion of OSCC-15 cells. It also enhanced the apoptotic rate of the OSCC­15 cells. Furthermore, the overexpression of KAI1/CD82 inhibited tumor growth in the xenograft model. The results demonstrated that the overexpression of KAI1/CD82 significantly inhibited the proliferation and invasion of human oral cancer cells, and inhibited tumor growth in the xenograft model. Therefore, KAI1/CD82 may be considered as a potential therapeutic target in oral cancer.

Nomograms for predicting long-term overall survival and cancer-specific survival in patients with major salivary gland cancer: a population-based study.

In this study, we aimed to develop and validate nomograms for predicting long-term overall survival (OS) and cancer-specific survival (CSS) in major salivary gland cancer (MSGC) patients. These nomograms were developed using a retrospective cohort (N=4218) from the Surveillance, Epidemiology, and End Results (SEER) database, and externally validated using an independent data cohort (N=244). We used univariate, and multivariate analyses, and cumulative incidence function to select the independent prognostic factors of OS and CSS. Index of concordance (c-index) and calibration plots were used to estimate the nomograms' predictive accuracy. The median follow-up period was 34 months (1-119 months). Of 4218 MSGC patients, 1320 (31.3%) died by the end of the follow-up; of these 1320 patients, 883 (20.9%) died of MSGC. The OS nomogram, which had a c-index of 0.817, was based on nine variables: age, sex, tumor site, tumor grade, surgery performed, radiation therapy and TNM classifications. The CSS nomogram, which had a c-index of 0.829, was based on the same nine variables plus race. External validation c-indexes were 0.829 and 0.807 for OS and CSS, respectively. Based on SEER database, we have developed nomograms predicting five- and eight-years OS and CSS for MSGC patients with perfect accuracy. These nomograms will help clinicians customize treatment and monitoring strategies in MSGC patients.

The role of perineural invasion on head and neck adenoid cystic carcinoma prognosis: a systematic review and meta-analysis.

OBJECTIVE: We performed a systematic review to assess the prognostic value of perineural invasion (PNI) for patients with head and neck adenoid cystic carcinoma. STUDY DESIGN: A literature search of MEDLINE and EMBASE was used to identify relevant literature up to December 2015. The primary outcomes of interest were overall survival, disease-free survival, and locoregional control. Study information and hazard ratios (HRs) were extracted, and HRs were pooled using the Mantel-Haenszel fixed-effects model and the DerSimonian and Laird random-effects model according to heterogeneity. RESULTS: Twenty-two studies and 1332 patients were included in this study. The PNI ratio was 43.2%. PNI was at increasing risk for overall survival (HR = 2.98; 95% confidence interval [CI] 2.00-4.46), disease-free survival (HR = 1.88; 95% CI, 1.42-2.49), and locoregional control (HR = 2.15; 95% CI, 1.48-3.13) with statistical significance. CONCLUSIONS: PNI is an independent factor for poor prognosis in patients with head and neck adenoid cystic carcinoma. Moreover, PNI poses a significantly higher threat to male patients and younger patients.

Nomograms predicting long-term overall survival and cancer-specific survival in head and neck squamous cell carcinoma patients.

This study aimed to develop nomograms to predict long-term overall survival and cancer-specific survival in patients with head and neck squamous cell carcinoma (HNSCC). We conducted prognostic analyses and developed nomograms predicting survival outcome using HNSCC patient data collected from the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute. An external dataset of 219 patients was used to validate the nomograms. Of 36,179 HNSCC patients, 9,627 (26.6%) died from HNSCC and 4,229 (11.7%) died from other causes. Median follow-up was 28 months (1-107 months). Nomograms predicting overall survival (OS) and cancer-specific survival (CSS) were developed according to 10 clinicopathologic factors (age, race, sex, tumor site, tumor grade, surgery, radiotherapy and TNM stage), with concordance indexes (C-indexes) of 0.719 and 0.741, respectively. External validation C-indexes were 0.709 and 0.706 for OS and CSS, respectively. Our results suggest that we successfully developed nomograms predicting five- and eight-year HNSCC patient OS and CSS with high accuracy. These nomograms could help clinicians tailor surgical, adjuvant therapeutic and follow-up strategies to more effectively treat HNSCC patients.

p12CDK2-AP1 interacts with CD82 to regulate the proliferation and survival of human oral squamous cell carcinoma cells.

p12 cyclin-dependent kinase 2 (CDK2)-associating protein 1 (p12CDK2-AP1) has been demonstrated to negatively regulate the activity of CDK2. However, the underlying molecular mechanism remains largely unknown. We aimed to determine the potential binding proteins of p12CDK2-AP1 and to elucidate the role of p12CDK2-AP1 in the regulation of the proliferation, invasion, apoptosis, and in vivo growth of human oral squamous cell carcinoma cells. The protein-protein interaction was predicted using computational decision templates. The predicted p12CDK2­AP1 interacting proteins were overexpressed in human oral squamous cell carcinoma OSCC-15 cells, and the protein binding was examined using co-precipitation (Co-IP). Cell proliferation and invasion were determined via MTT assay and Transwell system, respectively. Cell apoptosis was evaluated using Annexin V-FITC/PI double staining followed by flow cytometric analysis. The in vivo growth of OSCC-15 cells was examined in nude mouse tumor xenografts. We found that overexpression of either p12CDK2-AP1 or CD82 significantly suppressed the proliferation and invasion but promoted the apoptosis of OSCC-15 cells (P<0.05). Importantly, combined overexpression of p12CDK2-AP1 and CD82 showed synergistic antitumor activity compared with the overexpression of a single protein alone (P<0.05). Additionally, the simultaneous overexpression of p12CDK2-AP1 and CD82 significantly suppressed the in vivo tumor growth of OSCC-15 cells in nude mice compared with the negative control (P<0.05). Our findings indicate that p12CDK2-AP1 interacts with CD82 to play a functional role in suppressing the in vitro and in vivo growth of OSCC-15 cells.

Transdifferentiation of bone marrow-derived mesenchymal stem cells into salivary gland-like cells using a novel culture method.

OBJECTIVES: To investigate the transdifferentiation of bone marrow-derived mesenchymal stem cells (BMSCs) into salivary gland-like cells via a novel culture method employing induction culture medium collected from salivary gland cells. RESULTS: Primary salivary gland cells were cultured, and after the first passage, the culture medium was collected for use as induction medium. BMSCs (passage 3) were cultured in either induction medium (induction group) or DMEM/F12 medium with 10 % (v/v) fetal bovine serum (control group) before seeding on three-dimensional collagen/chitosan scaffolds and subcutaneous transplantation into nude mice. The in vitro and in vivo transdifferentiation of BMSCs into salivary gland-like cells was evaluated by immunocytochemical analysis of α-amylase and cytokeratin-8 (CK-8) expression. Salivary gland-like cells cultured using this novel method maintained excellent biostability and exhibited relatively stable expression of α-amylase and CK-8 in vitro and in vivo. CONCLUSION: This novel culture method is feasible for inducing the transdifferentiation of BMSCs into salivary gland-like cells.

Downregulation of p53 promotes in vitro perineural invasive activity of human salivary adenoid cystic carcinoma cells through epithelial-mesenchymal transition-like changes.

Salivary adenoid cystic carcinoma (SACC) is a malignant tumor that is characterized by perineural invasion (PNI). p53 is an essential tumor-suppressor gene and p53 mutations play a critical role in tumor occurrence and progression (e.g., pancreatic, prostate and head and neck cancer). However, the regulatory role of the p53 gene in SACC and the PNI process remains unknown. In the present study, we employed RNA interference technique to downregulate p53 gene expression in SACC-83 cells to explore the role of p53 in the PNI process. Our results showed that the downregulation of the p53 gene induced significant 'epithelial-mesenchymal transition (EMT)-like changes' in SACC-83 cells, including decreased expression levels of epithelial markers (E-cadherin, EMA and CK5) and increased expression levels of mesenchymal markers (vimentin, N-cadherin and C-cadherin). The downregulation of p53 also caused a lower apoptotic index of Annexin V-FITC/PI and a lower number of SACC-83 cells in the second G0/G1 phase of the cell cycle. Furthermore, the downregulation of the p53 gene resulted in a significant increase in PNI activity in the SACC-83 cells. Thus, our findings revealed that downregulation of p53 promoted in vitro PNI activity through 'EMT-like changes' in SACC-83 cells. The present study suggests the essential regulatory role of p53 in the PNI activity of SACC cells, and implies that p53 may be a new target gene for the clinical treatment of SACC.